Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Influence of mechanically-induced dilatation on the shape memory behavior of amorphous polymers at large deformation

Influence of mechanically-induced dilatation on the shape memory behavior of amorphous polymers... Abstract In this study, we explore the influence of mechanically-induced dilatation on the thermomechanical and shape memory behavior of amorphous shape memory polymers (SMPs) at large deformation. The uniaxial tension, glass transition, stress relaxation and free recovery behaviors are examined with different strain levels (up to 340% engineering strain). A multi-branched constitutive model that incorporates dilatational effects on the polymer relaxation time is established and applied to assist in discussions and understand the nonlinear viscoelastic behaviors of SMPs. It is shown that the volumetric dilatation results in an SMP network with lower viscosity, faster relaxation, and lower \(T_{g}\). The influence of the dilatational effect on the thermomechanical behaviors is significant when the polymers are subject to large deformation or in a high viscosity state. The dilation also increases the free recovery rate of SMP at a given recovery temperature. Even though the tested SMPs are far beyond their linear viscoelastic region when a large programming strain is applied, the free recovery behavior still follows the time-temperature superposition (TTSP) if the dilatational effect is considered during the transformation of time scales; however, if the programming strain is different, TTSP fails in predicting the recovery behavior of SMPs because the network has different entropy state and driving force during shape recovery. Since most soft active polymers are subject to large deformation in practice, this study provides a theoretical basis to better understand their nonlinear viscoelastic behaviors, and optimize their performance in engineering applications. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Mechanics of Time-Dependent Materials Springer Journals

Influence of mechanically-induced dilatation on the shape memory behavior of amorphous polymers at large deformation

Loading next page...
 
/lp/springer-journals/influence-of-mechanically-induced-dilatation-on-the-shape-memory-rWcM5x0jJ8

References (57)

Publisher
Springer Journals
Copyright
2018 Springer Science+Business Media B.V., part of Springer Nature
ISSN
1385-2000
eISSN
1573-2738
DOI
10.1007/s11043-018-9376-1
Publisher site
See Article on Publisher Site

Abstract

Abstract In this study, we explore the influence of mechanically-induced dilatation on the thermomechanical and shape memory behavior of amorphous shape memory polymers (SMPs) at large deformation. The uniaxial tension, glass transition, stress relaxation and free recovery behaviors are examined with different strain levels (up to 340% engineering strain). A multi-branched constitutive model that incorporates dilatational effects on the polymer relaxation time is established and applied to assist in discussions and understand the nonlinear viscoelastic behaviors of SMPs. It is shown that the volumetric dilatation results in an SMP network with lower viscosity, faster relaxation, and lower \(T_{g}\). The influence of the dilatational effect on the thermomechanical behaviors is significant when the polymers are subject to large deformation or in a high viscosity state. The dilation also increases the free recovery rate of SMP at a given recovery temperature. Even though the tested SMPs are far beyond their linear viscoelastic region when a large programming strain is applied, the free recovery behavior still follows the time-temperature superposition (TTSP) if the dilatational effect is considered during the transformation of time scales; however, if the programming strain is different, TTSP fails in predicting the recovery behavior of SMPs because the network has different entropy state and driving force during shape recovery. Since most soft active polymers are subject to large deformation in practice, this study provides a theoretical basis to better understand their nonlinear viscoelastic behaviors, and optimize their performance in engineering applications.

Journal

Mechanics of Time-Dependent MaterialsSpringer Journals

Published: Feb 1, 2019

Keywords: Solid Mechanics; Classical Mechanics; Characterization and Evaluation of Materials; Polymer Sciences

There are no references for this article.